Madalynne Fedoruk and Darian Carey, Dixie State University
Life Sciences
For at least three decades, infection with chytrid fungus (Batrachochytrium dendrobatidis) has been a major cause of population decline in amphibians worldwide. This pathogen has been found in canyon tree frogs (Hyla arenicolor) in Zion National Park; previous studies suggested that population sizes decreased in frogs infected with the fungus; but our studies indicated that these frogs were resistant. We hypothesized that chytrid infection in the Zion Canyon tree frogs were not lethal, but other environmental factors caused populations to fluctuate. Canyon tree frogs were captured and swabbed in each of nine canyons in and around Zion National Park during the summer of 2014, and total frog populations were counted in each study canyon. The swabs were analyzed for the presence of chytrid DNA, and infection rates and population sizes were compared with data from 2011-2013. We found that the presence or absence of chytrid had no influence on population size in a particular canyon; population sizes were more dependent on precipitation. The Zion canyon tree frogs resist this normally lethal disease; how they evade it will be the goal of future studies.